Cary Education Seminar March 9, 1995 Clinical Networking DICOM Digital Imaging COmmunications in Medicine

Cary Education Seminar

March 9, 1995

Clinical Networking

DICOM Digital Imaging

COmmunications in Medicine


March 9, 1995

Clinical Networking

Communication Protocols: Key to

Connectivity Layered Model, each layer performs a specific function Set of Services and Protocols Connectivity requires sharing a complete protocol Communication requires a shared Semantic Context


March 9, 1995

Clinical Networking

ISO Reference Model

LLCMAC

PHYSICAL

DATA LINK

NETWORK

TRANSPORT

SESSION

PRESENTATION

APPLICATION

Fiber, Coax, UTP, µWave

Bridges

Repeaters

Routers

End-to-End communication

Data Formatting

File Transfer, E-mail, VT, DIR

Ethernet, FDDI, etc.

Internetworking

Protocol Converters

Synchronization


March 9, 1995

Clinical Networking

Communication Standards

Protocols are defined by standards A Standard is an agreement which may be

voluntary, Government mandated, or International Law

Protocols may also be proprietary


March 9, 1995

Clinical Networking

Who Defines Communication

Standards? User Consortia (e.g., HL7) Organizations (e.g., NEMA, IEEE) US Government Agencies (e.g., ANSI, NIST) Foreign Government Agencies (e.g., CEN) United Nations (e.g., ISO, CCITT)


March 9, 1995

Clinical Networking

ACR-NEMA

1982 - ACR and NEMA form a joint committee 1985 - Publication of Version 1.0 1988 - Compression and Mag Tape Standards 1988 - Publication of Version 2.0 1989 - Began work on Network Version with HIS/RIS


March 9, 1995

Clinical Networking

DICOM The name was changed to separate the standard

from the originating body 1991 - Release of Parts 1 and 8 of DICOM 1992 - RSNA demonstration, Part 8 1993 - DICOM Parts 1-9 approved,

RSNA demonstration of ALL parts 1994 - Part 10: Media Storage and File Format 1995 - Parts 11,12, and 13 plus Supplements


March 9, 1995

Clinical Networking

The Parts of the DICOM Standard Part 1 - Introduction and Overview

Part 2 - Conformance Part 3 - Information Object Definitions Part 4 - Service Class Definitions Part 5 - Data Structures & Semantics Part 6 - Data Element Listing and Typing Part 7 - Message Exchange Protocol Part 8 - Network Support for Message Exchange Part 9 - Point-to-Point Support


March 9, 1995

Clinical Networking

The Parts of the DICOM Standard

Part 10 - Media Storage and File Format Part 11 - Media Storage Application Profiles Part 12 - Media Formats and Physical Media Part 13 - Print Management Point-to-Point


March 9, 1995

Clinical Networking

DICOM Application Domain

MAGN

ETOM

Information Management System

Storage, Query/Retrieve, Storage, Query/Retrieve, Study ComponentStudy Component

Query/Retrieve, Patient & Study ManagementQuery/Retrieve, Patient & Study Management

Query/RetrieveQuery/RetrieveResults ManagementResults Management

Print ManagementPrint Management

Media ExchangeMedia Exchange

LiteBox


March 9, 1995

Clinical Networking

Summary of DICOM Features

NETWORK PROTOCOL DICOM incorporates negotiation to permit nodes to agree on

the functions to be performed

MESSAGE ENCODING DICOM defines 24 data types (V2.0 had 4) DICOM message encoding includes JPEG compression (17

varients) DICOM includes encapsulated image and multi-frame syntaxes DICOM supports multiple character repertoires


March 9, 1995

Clinical Networking

Summary of DICOM Features OBJECT DATA MODEL

DICOM is based on a completely specified data model DICOM includes a robust UID mechanism

DATA DICTIONARY DICOM includes a large number of new data elements

SERVICE CLASSES DICOM defines classes of service for specific applications (e.g.

image management, printing) and conformance levels


March 9, 1995

Clinical Networking

Summary of DICOM Features

Off-Line Media Support DICOM defines a directory structure and media profiles

CONFORMANCE DICOM requires conformance statements and contains detailed

conformance requirements


March 9, 1995

Clinical Networking

Network Protocol

LLC

ISO NETWORK

ISO TRANSPORT

ISO SESSION KERNEL

ISO PRESENTATION

ISO Association Control Service Element (ACSE)

TCP

IP

DICOM Upper layer

protocol for TCP/IP

Session /

Transport / Network

(STN)

Data Link

Physical (50-pin) Ethernet, FDDI, ISDN, etc.

DICOM Application Entity

Medical Imaging Application

ISO Upper Layer Service boundary

Point-to-point Network Environment


March 9, 1995

Clinical Networking

DICOM Terminology

DICOM Message Service Element (DIMSE) - The set of DICOM Application Layer communication services.

DIMSE Service Group (DSG) - A subset of the full DIMSE services which is applicable to a specific IOD.

Information Object Definition (IOD) - A data abstraction of a class of real-world objects. A collection of related attributes (data elements).


March 9, 1995

Clinical Networking

DICOM Terminology

Service Class - A set of functionality relating to a single type or real-world activity. Composed of a set of SOP Classes plus rules and associated semantics.

Service-Object-Pair Class (SOP) - The atomic unit of DICOM functionality. Composed of an IOD and a DIMSE Service Group plus restrictions or extensions of the IOD. (Equivalent to an Object Class)


March 9, 1995

Clinical Networking

Service-Object Pair Class

SOPSOP

Data DictionaryData Dictionary

Real-World ObjectReal-World Object

Information Object Information Object DIMSE Service GroupDIMSE Service Group


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Clinical Networking

DICOM Service Classes

Composite Verification Storage Query/Retrieve Study Content Notification

Normalized Patient Management Study Management Results Management Basic Print Management


March 9, 1995

Clinical Networking

Conformance

DICOM Part 2 specifies the structure of a conformance statement

DICOM does not specify a test suite or a compliance verification mechanism

All DICOM implementations must be supported by a properly constructed conformance statement


March 9, 1995

Clinical Networking

DICOM Conformance Statement Implementation Model which describes the Application

Entities in the implementation Detailed specification of each Application Entity

SOP Classes supported policies for initiation and acceptance of associations

Presentation Contexts SOP options Supported communications protocols Specializations Configuration


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Clinical Networking

Purpose of a Conformance Statement

Allow a user to determine which optional components of the DICOM Standard are supported by a particular implementation, and what extensions or specializations an implementation adds.

By comparing the Conformance Statements from two implementations, a knowledgeable user should be able to determine whether or not interoperability is possible.


March 9, 1995

Clinical Networking

DICOM Conformance Testing

No Formal Mechanism is Defined in the Standard Committee for the Advancement of DICOM Define initial test plan and cross-connect matrix Future RFP for organization to monitor the process Problem: How to Map DICOM Conformance

Statements into Test Plans


March 9, 1995

Clinical Networking

The DICOM Explosion

Joint CEN-DICOM development Medicom = DICOM MIPS 95 work is underway with JIRA IS&C Harmonization is also in progress HL7 Harmonization continuing interest New DICOM organization

Companies: NEMA and non-NEMA ACR, ACC, CAP, ... individuals


March 9, 1995

Clinical Networking

Summary

Networking is a critical component of all medical imaging systems

Support for Open Communication Standards is a MUST

DICOM is here, NOW DICOM products exist on the market DICOM is emerging as THE common protocol for

medical image communication - WORLD WIDE!

Documents

Cary Education Seminar March 9, 1995 Clinical Networking DICOM Digital Imaging COmmunications in Medicine